1. Departments of Surgery, Leiden University Medical Center, Leiden, Netherlands
2. Medical Oncology, Leiden University Medical Center, Leiden, Netherlands
3. Medical Statistics, Leiden University Medical Center, Leiden, Netherlands
4. Department of Internal Medicine, Albert Schweitzer Hospital, Dordrecht, the Netherlands
5. Department of Internal Medicine, Reinier de Graaff Hospital, Delft, the Netherlands
6. Dutch Breast Cancer Research Group, Amsterdam, the Netherlands
7. Department of Surgery, Netherlands Cancer Institute, Amsterdam, the Netherlands